Environment Economic Dispatch Under Security Operation Constraint Of Power System

With becoming increasingly serious problems of energy and environment, new energy has been rapid development. The wind power as a renewable and clean energy has been listed as national key development program in the green energy industries. However, the random and intermittent characteristic of wind power is a challenge for grid’s dispatch. Therefore, the study for environmental economic dispatch of grid integrating the wind power has become a hot topic.In this paper, we study the modeling and computation of environment economics dispatch in power system with wind power. For the reserve capacity shortfall caused by wind power prediction error, we adopt the compensation manner by purchasing interruptible load, and set up the environment economic dispatch model. The objective function in the model considers the costs of unit coal consumption, environmental pollution, valve-point effect and the compensation of interruptible load. For the uncertainty nature of wind power, under the assumption that the wind power obeys two-parameter Weibull distribution, we forecast the output of wind power via the wind power conversion curve and the Monte Carlo method. Considering the case of DC power flow, we use conditional value-at-risk (CVaR) approach to characterize the probability of each branch’s load factor not meet the safe operation. Then an environment economic dispatch model under operation security constraint of power system is formulated. Finally, the single-period environmental economic dispatch is extended to multi-period dispatch problem combining with unit climbing constraints.For the solution method of the proposed model in this paper, we present a new class of stochastic optimization algorithm in which the penalty function method, smoothing techniques and sample average method are adopted. Firstly, use the penalty function to deal with the model so that the CVaR constraint does not be involved in the constraints. Secondly, we use the smoothing approach to deal with the discontinuous term in the model. Finally, IEEE-30 node system to validate the model and solution algorithm. We analyze the effect of cost (objective value) by different CVaR value, confidence level, output of wind power, as well the effect of interruptible load and different error of wind power prediction. The results show the validity of proposed model and solution method.